The United Nations says fighting and other strife is preventing aid workers from reaching 100,000 people in Darfur who need help.

The spokeswoman for the U.N. Office for the Coordination of Humanitarian Affairs, Jennifer Abrahamson, told VOA Wednesday that, although aid workers have been granted much more access to displaced populations in the war-torn Darfur region in western Sudan, there are still people who cannot be reached.

"There are pockets of insecurity and fighting that's going on in the north and south, right now," she said. "So many areas have been temporarily marked with no-go zones. We're constantly assessing those areas to enable us to get back in as soon as possible."

Ms. Abrahamson says the insecurity results from fighting between government troops and the two main rebel groups operating there, as well as from attacks by a pro-government militia known as "Janjaweed," and regular banditry.

She says this insecurity is preventing aid from reaching 100,000 people, mostly in areas south of El Fashir and Nyala.

A recent American-sponsored U.N. resolution says the Sudanese government must disarm the Janjaweed; protect the local population from attacks; and generally restore security to Darfur or face possible sanctions against its oil industry.

Government officials say they are doing all they can to bring security back to Darfur and have made the area much safer than it was before.

Secretary of State Colin Powell recently told a Senate committee that fighting in Darfur constitutes a genocide in which the Janjaweed, said to be an "Arab militia", target black Africans, a charge the Sudanese government vehemently denies.

A spokesman for the Sudan office of the World Food Program, Peter Smerdon, says the U.N. resolution has had the effect of decreasing insecurity in Darfur, which has helped food and other aid to get through to affected populations.

But, he says, Mr. Powell's labeling of the conflict as "genocide" has made no difference to aid efforts.

"The numbers that we're trying to reach in September, 1.2 million, needed food before it was labeled genocide and will need food after," said Mr. Smerdon. "So I don't think donors have reacted on a level of whether its genocide or not. They've reacted because there's been a need."

According to the latest U.N. figures, more than 1.8 million people are being affected by the war in Darfur. Of these, some 1.4 million have been displaced by the fighting.